There is increasing interest in the use of electroactive polymers in medical devices. For example, electroactive polymers can be used to make implantable actuators that can be controlled by electrical stimulation. In such medical devices, the electroactive polymer requires a source of electrical power. For implanted medical devices, where the power supply is external to the patient, the electroactive polymer can be connected to the external power supply via an electrical lead (e.g., through a catheter). Another approach is to provide the implanted medical device with a receiver coil connected to the electroactive polymer and provide electrical power by inductive coupling with an externally located transmitter coil. However, both of these approaches can cause problems when the patient is subjected to an MRI examination. In particular, the powerful RF fields generated by an MRI machine can produce inductive currents in the electrical leads or coils. Heating of the leads or coils by the induced current can cause injury to the patient.
Another approach for providing a power supply is to implant a battery along with the medical device. However, this approach requires the implantation of another component into the patient's body (batteries can be bulky) and risks the possibility of potentially toxic chemicals leaking from the battery. Thus, there is a need for an alternative power supply for medical devices using electroactive polymers.